Bio 311C Final QUESTIONS AND ANSWERS A+ GRADED
A suspension of algae is incubated in a flask in the presence of both light and
CO2. When it is transferred to the dark, the reduction of 3-phosphoglycerate
(3PG) to glyceraldehyde 3-phosphate (G3P) is blocked, and the concentration of
ribulose 1,5-bisphosphate (RuBP) declines. Why does the RuBP concentration
decline?
A) RuBP is synthesized from G3P.
B) G3P is converted to glucose.
C) RuBP is used to fix CO2.
D) Both a and b
E) Both a and c
E
How does a protein kinase cascade amplify an intercellular signal?
A) Protein kinase molecules open cell junctions, amplifying the intercellular
signal.
B) The activated G protein binds and activates a second protein, amplifying the
signal.
C) Nitric oxide opens cell channels, which allows protein kinase molecules to
move quickly from cell to cell.
D) Second messengers create shortcuts that create multiple cascades.
E) One activated receptor kinase molecule can trigger the activation of thousands
of proteins
E
Vitamin A is a relatively small, lipid-soluble molecule that can behave as a steroid
hormone. Most likely its receptor
A) is an ion channel receptor.
B) is a protein kinase receptor.
C) involves a G protein.
D) is not connected to the plasma membrane.
E) does not exist; vitamin A does not have a receptor.
E
When a mouse cell and a human cell are fused, the membrane proteins of the two
cells become uniformly distributed over the surface of the hybrid cell. This
occurs becauseA) many proteins can move around within the bilayer.B) all
proteins are anchored within the membrane.C) proteins are asymmetrically
distributed within the membrane.D) all proteins in the plasma membrane are
peripheral.E) different membranes contain different proteins
A
The LDL receptor is an integral protein that crosses the plasma membrane, with
portions of the protein extending both outside and into the interior of the cell. The
amino acid side chains (R groups) in the region of the protein that crosses the
inner part of the membrane are most likelyA) charged.B) hydrophilic.C)
hydrophobic.D) carbohydrates.E) lipids.
C
, Houseplants adapted to indoor temperatures may die if they are left outdoors,
because in a cold environment theirA) DNA cannot function.B) membranes lack
adequate fluidity.C) photosynthesis is impaired.D) membranes contain too many
unsaturated fatty acids.E) membranes need more cholesterol.
B
Cyanide inhibits the enzyme in the mitochondrial electron transport chain that
reduces O2to water. Suppose that you add cyanide to a suspension of muscle
cells from a rat. Which statement given below is the most accurate with respect to
the effects of cyanide on glucose catabolism?A) The citric acid cycle and
glycolysis would be inhibited.B) The citric acid cycle would be inhibited, but
glycolysis would not. Ethanol accumulates.C) The citric acid cycle would be
inhibited, but glycolysis would not. Lactic acid accumulates.D) The citric acid
cycle and glycolysis would be stimulated.E) The citric acid cycle would not be
inhibited, but glycolysis would.
C
The folds of the inner mitochondrial membraneA) increase the volume of the
mitochondrial matrix.B) create a large membrane surface for reactions within the
mitochondrion.C) increase the number of ribosomes within the membrane.D)
anchor the mitochondrial DNA.E) have no known purpose.
B
The membrane surrounding each organelleA) is composed of hydrophobic
proteins.B) regulates movement into and out of the organelle.C) is studded with
ribosomes.D) allows for interactions among molecules.E) is perforated with
pores.
B
The surface area-to-volume ratio of a cellA) can be increased by increasing the
volume of the cell.B) can be decreased by decreasing the surface area.C)
explains why cells are small.D) is of little significance to the maintenance of cell
homeostasis.E) None of the above
C
The role of organelles is toA) provide structural support for the cell.B) decrease
the flow of materials into and out of the cell.C) increase the efficiency of cellular
activities.D) provide a means of cellular reproduction.E) regulate the flow of
materials inside the cell.
C
If all the lysosomes within a cell suddenly ruptured, what would be the most likely
result?A) The macromolecules in the cytosol would break down.B) More proteins
would be made.C) The DNA within mitochondria would break down.D) The
mitochondria and chloroplasts would divide.E) There would be no change in cell
function.
A
The light reactions of photosynthesis provides the Calvin cycle withA) protons
and electrons.B) CO2 and glucose.C) water and photons.D) light and
chlorophyll.E) ATP and NADPH.
E
A suspension of algae is incubated in a flask in the presence of both light and
CO2. When it is transferred to the dark, the reduction of 3-phosphoglycerate
(3PG) to glyceraldehyde 3-phosphate (G3P) is blocked, and the concentration of
ribulose 1,5-bisphosphate (RuBP) declines. Why does the RuBP concentration
decline?
A) RuBP is synthesized from G3P.
B) G3P is converted to glucose.
C) RuBP is used to fix CO2.
D) Both a and b
E) Both a and c
E
How does a protein kinase cascade amplify an intercellular signal?
A) Protein kinase molecules open cell junctions, amplifying the intercellular
signal.
B) The activated G protein binds and activates a second protein, amplifying the
signal.
C) Nitric oxide opens cell channels, which allows protein kinase molecules to
move quickly from cell to cell.
D) Second messengers create shortcuts that create multiple cascades.
E) One activated receptor kinase molecule can trigger the activation of thousands
of proteins
E
Vitamin A is a relatively small, lipid-soluble molecule that can behave as a steroid
hormone. Most likely its receptor
A) is an ion channel receptor.
B) is a protein kinase receptor.
C) involves a G protein.
D) is not connected to the plasma membrane.
E) does not exist; vitamin A does not have a receptor.
E
When a mouse cell and a human cell are fused, the membrane proteins of the two
cells become uniformly distributed over the surface of the hybrid cell. This
occurs becauseA) many proteins can move around within the bilayer.B) all
proteins are anchored within the membrane.C) proteins are asymmetrically
distributed within the membrane.D) all proteins in the plasma membrane are
peripheral.E) different membranes contain different proteins
A
The LDL receptor is an integral protein that crosses the plasma membrane, with
portions of the protein extending both outside and into the interior of the cell. The
amino acid side chains (R groups) in the region of the protein that crosses the
inner part of the membrane are most likelyA) charged.B) hydrophilic.C)
hydrophobic.D) carbohydrates.E) lipids.
C
, Houseplants adapted to indoor temperatures may die if they are left outdoors,
because in a cold environment theirA) DNA cannot function.B) membranes lack
adequate fluidity.C) photosynthesis is impaired.D) membranes contain too many
unsaturated fatty acids.E) membranes need more cholesterol.
B
Cyanide inhibits the enzyme in the mitochondrial electron transport chain that
reduces O2to water. Suppose that you add cyanide to a suspension of muscle
cells from a rat. Which statement given below is the most accurate with respect to
the effects of cyanide on glucose catabolism?A) The citric acid cycle and
glycolysis would be inhibited.B) The citric acid cycle would be inhibited, but
glycolysis would not. Ethanol accumulates.C) The citric acid cycle would be
inhibited, but glycolysis would not. Lactic acid accumulates.D) The citric acid
cycle and glycolysis would be stimulated.E) The citric acid cycle would not be
inhibited, but glycolysis would.
C
The folds of the inner mitochondrial membraneA) increase the volume of the
mitochondrial matrix.B) create a large membrane surface for reactions within the
mitochondrion.C) increase the number of ribosomes within the membrane.D)
anchor the mitochondrial DNA.E) have no known purpose.
B
The membrane surrounding each organelleA) is composed of hydrophobic
proteins.B) regulates movement into and out of the organelle.C) is studded with
ribosomes.D) allows for interactions among molecules.E) is perforated with
pores.
B
The surface area-to-volume ratio of a cellA) can be increased by increasing the
volume of the cell.B) can be decreased by decreasing the surface area.C)
explains why cells are small.D) is of little significance to the maintenance of cell
homeostasis.E) None of the above
C
The role of organelles is toA) provide structural support for the cell.B) decrease
the flow of materials into and out of the cell.C) increase the efficiency of cellular
activities.D) provide a means of cellular reproduction.E) regulate the flow of
materials inside the cell.
C
If all the lysosomes within a cell suddenly ruptured, what would be the most likely
result?A) The macromolecules in the cytosol would break down.B) More proteins
would be made.C) The DNA within mitochondria would break down.D) The
mitochondria and chloroplasts would divide.E) There would be no change in cell
function.
A
The light reactions of photosynthesis provides the Calvin cycle withA) protons
and electrons.B) CO2 and glucose.C) water and photons.D) light and
chlorophyll.E) ATP and NADPH.
E
